If an unresolved report for the same target account already exists,
no new notification is generated

* Add option to block direct messages from people you don't follow

Fix #5326

* If the DM responds to a toot by recipient, allow it through

* i18n: Update Polish translation (for #5669) (#5673)

* Separate notifications preferences from general preferences

* Refine settings/notifications/show

* remove preferences.notifications